From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-333748-1524840420-2-3972302058964311535 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, MAILING_LIST_MULTI -1, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1524840419; b=Y9OWEH/nvQQTAsHbNcFsbD2DU27WGoT3INRplmWW1xWOD9W1DG JYPvQFWE/cQCXyh10q+qunjWFTIOCjFczrFxYWOlvREx9CNbDg/ad3EcFG/7FyI7 bZQkJQMDTzy8mwATeIgUMSPWIFi0Rp7yQCWivoHrHjrKxxVqxWSirhsSlRuQEyOu l3phKnLS/5fSCQktwgFsCynjvshR9YiMJIi0LZoN0GZHnO3b8rdQZZUEaz3M7Nok pXpZ4awE02RfNMgtAQZn309IzE3m1tIx2RCrPVLrvGFo/mhqhqxYNlUUDqvLrpfC Ma6Ed027RWsK/yfoP1LTUjyoAFKtwjrhS8AQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=fm2; t=1524840419; bh=rlSwnbx7IGGQ8tVHZWYE9TwXNSOt5i BbDNYyKQbgQOA=; b=faw3TFH+dZnNFMU92zo6rTnkznI0HieJK2C9OUXkFWfhro IHd7NKIg68TwVjKf6GnYmNplhN1XWpuuj+ApY7pnf4nyPZn+DXpWLuJzpJ9J4Hos iVqiEyXJr1zWBYgSigVTKEfwld8xo7uxtwDdGGs0CCdBGLDP7ZOjiIl5kdJHpein TCOspVglGL0+eS31IjJSRy8OWDvLjv94K5I48FYX6sRbMBbm7xeNvRT/ONQ5RJGB UAZhtBKVj7VDoqDNp0OFT/vddBxMn+/h6JW1JN8XNYnsDYAwiGNAenJ/uCfO/Vhv v7cJWrmtaMHCv4gd2ww8A+s1jNEpvd9RtBKW7lVw== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfDoY+OUhkv7wOt+ll0rwQdnCkmwVOhWcPlA+JPBvRKHISMDulHWA+D2FII56MdhYesCZjoPaX4wCQGSYKNv4a4YSh1DRULnXPafTQfIz5ESGAxWHdHKR HgXhM5fbSrFBhaHgwRRGannz7VsbWLAVhr9z/1B3ezeioLpQy/1ji79+7WXYvtDCF+5+/GL/sFkSJ/50b4sxzUR9VRa6KVIPT7FBA6x5niNi6xC9iOePuPvu X-CM-Analysis: v=2.3 cv=WaUilXpX c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=IkcTkHD0fZMA:10 a=Kd1tUaAdevIA:10 a=VnNF1IyMAAAA:8 a=ag1SF4gXAAAA:8 a=Y4F1kmRjT2bv8szmQG4A:9 a=QEXdDO2ut3YA:10 a=Yupwre4RP9_Eg_Bd0iYG:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934025AbeD0Oqm (ORCPT ); Fri, 27 Apr 2018 10:46:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:53692 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934393AbeD0OH6 (ORCPT ); Fri, 27 Apr 2018 10:07:58 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 910F121892 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Schwidefsky Subject: [PATCH 4.14 53/80] s390: do not bypass BPENTER for interrupt system calls Date: Fri, 27 Apr 2018 15:58:46 +0200 Message-Id: <20180427135735.630826274@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180427135732.928644313@linuxfoundation.org> References: <20180427135732.928644313@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Martin Schwidefsky [ Upstream commit d5feec04fe578c8dbd9e2e1439afc2f0af761ed4 ] The system call path can be interrupted before the switch back to the standard branch prediction with BPENTER has been done. The critical section cleanup code skips forward to .Lsysc_do_svc and bypasses the BPENTER. In this case the kernel and all subsequent code will run with the limited branch prediction. Fixes: eacf67eb9b32 ("s390: run user space and KVM guests with modified branch prediction") Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/entry.S | 1 + 1 file changed, 1 insertion(+) --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -1375,6 +1375,7 @@ cleanup_critical: stg %r15,__LC_SYSTEM_TIMER 0: # update accounting time stamp mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER + BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP # set up saved register r11 lg %r15,__LC_KERNEL_STACK la %r9,STACK_FRAME_OVERHEAD(%r15)